Efficient signaling of picture size and partitioning information

ABSTRACT

A method of efficient signalizing of picture size and partitioning information in a video bitstream, is performed by at least one processor and includes obtaining, from a sequence parameter set (SPS) to which a coded picture refers, a flag indicating whether the picture size and partitioning information of the coded picture is included in the SPS, and determining whether the obtained flag indicates that the picture size and partitioning information is included in the SPS. The method further includes based on the flag being determined to indicate that the picture size and partitioning information is included in the SPS, obtaining, from the SPS, the picture size and partitioning information, and based on the flag being determined to indicate that the picture size and partitioning information is not included in the SPS, obtaining, from a video parameter set (VPS), the picture size and partitioning information that is included in the VPS.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Continuation of U.S. patent application Ser. No.17/478,442 filed Sep. 17, 2021, which is a Continuation of U.S. patentapplication Ser. No. 17/026,967 filed Sep. 21, 2020, now U.S. Pat. No.11,178,418 issued on Nov. 16, 2021, which claims priority from U.S.Provisional Patent Application No. 62/907,344, filed on Sep. 27, 2019,in the U.S. Patent and Trademark Office, which are incorporated hereinby reference in their entirety.

BACKGROUND 1. Field

Methods and apparatuses consistent with embodiments relate to videocoding, and more particularly, a method and an apparatus for efficientsignalizing of picture size and partitioning information in a videobitstream.

2. Description of Related Art

In block-based hybrid video coding, each picture is partitioned intoblocks of samples, and multiple blocks within a picture are aggregatedto form slices as independently decodable entities. For block-basedvideo coding, a picture may be partitioned into several blocks, whichmay also be referred to as coding tree units (CTUs), coding units (CUs),and/or coding blocks (CBs).

FIG. 1 shows an example of a partitioning structure of High EfficiencyVideo Coding (HEVC). HEVC employs a quad-tree coding block partitioningstructure that enables a flexible use of large and small coding,prediction, and transform blocks.

In Versatile Video Coding (VVC), a set of syntax elements specifying apicture size, sub-picture partitioning information, tile partitioninginformation, rectangular slice partitioning information and conformancewindow offsets is repeatedly signaled in parameter sets.

SUMMARY

According to embodiments, a method of efficient signalizing of picturesize and partitioning information in a video bitstream, is performed byat least one processor and includes obtaining, from a sequence parameterset (SPS) to which a coded picture refers, a flag indicating whether thepicture size and partitioning information of the coded picture isincluded in the SPS, and determining whether the obtained flag indicatesthat the picture size and partitioning information is included in theSPS. The method further includes, based on the flag being determined toindicate that the picture size and partitioning information is includedin the SPS, obtaining, from the SPS, the picture size and partitioninginformation, and based on the flag being determined to indicate that thepicture size and partitioning information is not included in the SPS,obtaining, from a video parameter set (VPS), the picture size andpartitioning information that is included in the VPS.

An apparatus for efficient signalizing of picture size and partitioninginformation in a video bitstream, includes at least one memoryconfigured to store computer program code, and at least one processorconfigured to access the at least one memory and operate according tothe computer program code. The computer program code includes firstobtaining code configured to cause the at least one processor to obtain,from a sequence parameter set (SPS) to which a coded picture refers, aflag indicating whether the picture size and partitioning information ofthe coded picture is included in the SPS, and first determining codeconfigured to cause the at least one processor to determine whether theobtained flag indicates that the picture size and partitioninginformation is included in the SPS. The computer program code furtherincludes second obtaining code configured to cause the at least oneprocessor to, based on the flag being determined to indicate that thepicture size and partitioning information is included in the SPS,obtain, from the SPS, the picture size and partitioning information, andthird obtaining code configured to cause the at least one processor to,based on the flag being determined to indicate that the picture size andpartitioning information is not included in the SPS, obtain, from avideo parameter set (VPS), the picture size and partitioning informationthat is included in the VPS.

A non-transitory computer-readable storage medium storing instructionsthat cause at least one processor to obtain, from a sequence parameterset (SPS) to which a coded picture refers, a flag indicating whether thepicture size and partitioning information of the coded picture isincluded in the SPS, and determine whether the obtained flag indicatesthat the picture size and partitioning information is included in theSPS. The instructions further cause the at least one processor to, basedon the flag being determined to indicate that the picture size andpartitioning information is included in the SPS, obtain, from the SPS,the picture size and partitioning information, and based on the flagbeing determined to indicate that the picture size and partitioninginformation is not included in the SPS, obtain, from a video parameterset (VPS), the picture size and partitioning information that isincluded in the VPS.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram of a partitioning structure of HEVC.

FIG. 2 is a simplified block diagram of a communication system accordingto embodiments.

FIG. 3 is a diagram of a placement of a video encoder and a videodecoder in a streaming environment, according to embodiments.

FIG. 4 is a functional block diagram of a video decoder according toembodiments.

FIG. 5 is a functional block diagram of a video encoder according toembodiments.

FIG. 6 is a flowchart illustrating a method of efficient signalizing ofpicture size and partitioning information in a video bitstream,according to embodiments.

FIG. 7 is a flowchart illustrating a method of efficient signalizing ofpicture size and partitioning information in a video bitstream,according to embodiments.

FIG. 8 is a simplified block diagram of an apparatus for efficientsignalizing of picture size and partitioning information in a videobitstream, according to embodiments.

FIG. 9 is a diagram of a computer system suitable for implementingembodiments.

DETAILED DESCRIPTION

FIG. 2 is a simplified block diagram of a communication system (200)according to embodiments. The communication system (200) may include atleast two terminals (210-220) interconnected via a network (250). Forunidirectional transmission of data, a first terminal (210) may codevideo data at a local location for transmission to the other terminal(220) via the network (250). The second terminal (220) may receive thecoded video data of the other terminal from the network (250), decodethe coded data and display the recovered video data. Unidirectional datatransmission may be common in media serving applications and the like.

FIG. 2 illustrates a second pair of terminals (230, 240) provided tosupport bidirectional transmission of coded video that may occur, forexample, during videoconferencing. For bidirectional transmission ofdata, each terminal (230, 240) may code video data captured at a locallocation for transmission to the other terminal via the network (250).Each terminal (230, 240) also may receive the coded video datatransmitted by the other terminal, may decode the coded data and maydisplay the recovered video data at a local display device.

In FIG. 2 , the terminals (210-240) may be illustrated as servers,personal computers and smart phones but the principles of embodimentsare not so limited. Embodiments find application with laptop computers,tablet computers, media players and/or dedicated video conferencingequipment. The network (250) represents any number of networks thatconvey coded video data among the terminals (210-240), including forexample wireline and/or wireless communication networks. Thecommunication network (250) may exchange data in circuit-switched and/orpacket-switched channels. Representative networks includetelecommunications networks, local area networks, wide area networksand/or the Internet. For the purposes of the present discussion, thearchitecture and topology of the network (250) may be immaterial to theoperation of embodiments unless explained herein below.

FIG. 3 is a diagram of a placement of a video encoder and a videodecoder in a streaming environment, according to embodiments. Thedisclosed subject matter can be equally applicable to other videoenabled applications, including, for example, video conferencing,digital TV, storing of compressed video on digital media including CD,DVD, memory stick and the like, and so on.

A streaming system may include a capture subsystem (313) that caninclude a video source (301), for example a digital camera, creating,for example, an uncompressed video sample stream (302). That samplestream (302), depicted as a bold line to emphasize a high data volumewhen compared to encoded video bitstreams, can be processed by anencoder (303) coupled to the camera (301). The encoder (303) can includehardware, software, or a combination thereof to enable or implementaspects of the disclosed subject matter as described in more detailbelow. The encoded video bitstream (304), depicted as a thin line toemphasize the lower data volume when compared to the sample stream, canbe stored on a streaming server (305) for future use. One or morestreaming clients (306, 308) can access the streaming server (305) toretrieve copies (307, 309) of the encoded video bitstream (304). Aclient (306) can include a video decoder (310), which decodes theincoming copy of the encoded video bitstream (307) and creates anoutgoing video sample stream (311) that can be rendered on a display(312) or other rendering device (not depicted). In some streamingsystems, the video bitstreams (304, 307, 309) can be encoded accordingto certain video coding/compression standards. Examples of thosestandards include ITU-T Recommendation H.265. Under development is avideo coding standard informally known as VVC. The disclosed subjectmatter may be used in the context of VVC.

FIG. 4 is a functional block diagram of a video decoder (310) accordingto embodiments.

A receiver (410) may receive one or more codec video sequences to bedecoded by the decoder (310); in the same or embodiments, one codedvideo sequence at a time, where the decoding of each coded videosequence is independent from other coded video sequences. The codedvideo sequence may be received from a channel (412), which may be ahardware/software link to a storage device, which stores the encodedvideo data. The receiver (410) may receive the encoded video data withother data, for example, coded audio data and/or ancillary data streams,that may be forwarded to their respective using entities (not depicted).The receiver (410) may separate the coded video sequence from the otherdata. To combat network jitter, a buffer memory (415) may be coupled inbetween receiver (410) and entropy decoder/parser (420) (“parser”henceforth). When receiver (410) is receiving data from a store/forwarddevice of sufficient bandwidth and controllability, or from anisosychronous network, the buffer (415) may not be needed, or can besmall. For use on best effort packet networks such as the Internet, thebuffer (415) may be required, can be comparatively large and canadvantageously of adaptive size.

The video decoder (310) may include a parser (420) to reconstructsymbols (421) from the entropy coded video sequence. Categories of thosesymbols include information used to manage operation of the decoder(310), and potentially information to control a rendering device such asa display (312) that is not an integral part of the decoder but can becoupled to it, as was shown in FIG. 4 . The control information for therendering device(s) may be in the form of Supplementary EnhancementInformation (SEI messages) or Video Usability Information (VUI)parameter set fragments (not depicted). The parser (420) mayparse/entropy-decode the coded video sequence received. The coding ofthe coded video sequence can be in accordance with a video codingtechnology or standard, and can follow principles well known to a personskilled in the art, including variable length coding, Huffman coding,arithmetic coding with or without context sensitivity, and so forth. Theparser (420) may extract from the coded video sequence, a set ofsubgroup parameters for at least one of the subgroups of pixels in thevideo decoder, based upon at least one parameters corresponding to thegroup. Subgroups can include Groups of Pictures (GOPs), pictures, tiles,slices, macroblocks, Coding Units (CUs), blocks, Transform Units (TUs),Prediction Units (PUs) and so forth. The entropy decoder/parser may alsoextract from the coded video sequence information such as transformcoefficients, quantizer parameter (QP) values, motion vectors, and soforth.

The parser (420) may perform entropy decoding/parsing operation on thevideo sequence received from the buffer (415), so to create symbols(421). The parser (420) may receive encoded data, and selectively decodeparticular symbols (421). Further, the parser (420) may determinewhether the particular symbols (421) are to be provided to a MotionCompensation Prediction unit (453), a scaler/inverse transform unit(451), an Intra Prediction unit (452), or a loop filter unit (454).

Reconstruction of the symbols (421) can involve multiple different unitsdepending on the type of the coded video picture or parts thereof (suchas: inter and intra picture, inter and intra block), and other factors.Which units are involved, and how, can be controlled by the subgroupcontrol information that was parsed from the coded video sequence by theparser (420). The flow of such subgroup control information between theparser (420) and the multiple units below is not depicted for clarity.

Beyond the functional blocks already mentioned, decoder (310) can beconceptually subdivided into a number of functional units as describedbelow. In a practical implementation operating under commercialconstraints, many of these units interact closely with each other andcan, at least partly, be integrated into each other. However, for thepurpose of describing the disclosed subject matter, the conceptualsubdivision into the functional units below is appropriate.

A first unit is the scaler/inverse transform unit (451). Thescaler/inverse transform unit (451) receives quantized transformcoefficient as well as control information, including which transform touse, block size, quantization factor, quantization scaling matrices,etc. as symbol(s) (421) from the parser (420). It can output blocksincluding sample values that can be input into aggregator (455).

In some cases, the output samples of the scaler/inverse transform (451)can pertain to an intra coded block; that is: a block that is not usingpredictive information from previously reconstructed pictures, but canuse predictive information from previously reconstructed parts of thecurrent picture. Such predictive information can be provided by an intrapicture prediction unit (452). In some cases, the intra pictureprediction unit (452) generates a block of the same size and shape ofthe block under reconstruction, using surrounding already reconstructedinformation fetched from the current (partly reconstructed) picture(456). The aggregator (455), in some cases, adds, on a per sample basis,the prediction information the intra prediction unit (452) has generatedto the output sample information as provided by the scaler/inversetransform unit (451).

In other cases, the output samples of the scaler/inverse transform unit(451) can pertain to an inter coded, and potentially motion compensatedblock. In such a case, a Motion Compensation Prediction unit (453) canaccess reference picture memory (457) to fetch samples used forprediction. After motion compensating the fetched samples in accordancewith the symbols (421) pertaining to the block, these samples can beadded by the aggregator (455) to the output of the scaler/inversetransform unit (in this case called the residual samples or residualsignal) so to generate output sample information. The addresses withinthe reference picture memory form where the motion compensation unitfetches prediction samples can be controlled by motion vectors,available to the motion compensation unit in the form of symbols (421)that can have, for example X, Y, and reference picture components.Motion compensation also can include interpolation of sample values asfetched from the reference picture memory when sub-sample exact motionvectors are in use, motion vector prediction mechanisms, and so forth.

The output samples of the aggregator (455) can be subject to variousloop filtering techniques in the loop filter unit (454). Videocompression technologies can include in-loop filter technologies thatare controlled by parameters included in the coded video bitstream andmade available to the loop filter unit (454) as symbols (421) from theparser (420), but can also be responsive to meta-information obtainedduring the decoding of previous (in decoding order) parts of the codedpicture or coded video sequence, as well as responsive to previouslyreconstructed and loop-filtered sample values.

The output of the loop filter unit (454) can be a sample stream that canbe output to the render device (312) as well as stored in the referencepicture memory (456) for use in future inter-picture prediction.

Certain coded pictures, once fully reconstructed, can be used asreference pictures for future prediction. Once a coded picture is fullyreconstructed and the coded picture has been identified as a referencepicture (by, for example, parser (420)), the current reference picture(456) can become part of the reference picture buffer (457), and a freshcurrent picture memory can be reallocated before commencing thereconstruction of the following coded picture.

The video decoder (310) may perform decoding operations according to apredetermined video compression technology that may be documented in astandard, such as ITU-T Rec. H.265. The coded video sequence may conformto a syntax specified by the video compression technology or standardbeing used, in the sense that it adheres to the syntax of the videocompression technology or standard, as specified in the videocompression technology document or standard and specifically in theprofiles document therein. Also necessary for compliance can be that thecomplexity of the coded video sequence is within bounds as defined bythe level of the video compression technology or standard. In somecases, levels restrict the maximum picture size, maximum frame rate,maximum reconstruction sample rate (measured in, for example megasamplesper second), maximum reference picture size, and so on. Limits set bylevels can, in some cases, be further restricted through HypotheticalReference Decoder (HRD) specifications and metadata for HRD buffermanagement signaled in the coded video sequence.

In embodiments, the receiver (410) may receive additional (redundant)data with the encoded video. The additional data may be included as partof the coded video sequence(s). The additional data may be used by thevideo decoder (310) to properly decode the data and/or to moreaccurately reconstruct the original video data. Additional data can bein the form of, for example, temporal, spatial, or signal-to-noise ratio(SNR) enhancement layers, redundant slices, redundant pictures, forwarderror correction codes, and so on.

FIG. 5 is a functional block diagram of a video encoder (303) accordingto embodiments.

The encoder (303) may receive video samples from a video source (301)(that is not part of the encoder) that may capture video image(s) to becoded by the encoder (303).

The video source (301) may provide the source video sequence to be codedby the encoder (303) in the form of a digital video sample stream thatcan be of any suitable bit depth (for example: 8 bit, 10 bit, 12 bit, .. . ), any colorspace (for example, BT.601 Y CrCB, RGB, . . . ) and anysuitable sampling structure (for example Y CrCb 4:2:0, Y CrCb 4:4:4). Ina media serving system, the video source (301) may be a storage devicestoring previously prepared video. In a videoconferencing system, thevideo source (301) may be a camera that captures local image informationas a video sequence. Video data may be provided as a plurality ofindividual pictures that impart motion when viewed in sequence. Thepictures themselves may be organized as a spatial array of pixels,wherein each pixel can include one or more samples depending on thesampling structure, color space, etc. in use. A person skilled in theart can readily understand the relationship between pixels and samples.The description below focuses on samples.

According to embodiments, the encoder (303) may code and compress thepictures of the source video sequence into a coded video sequence (543)in real time or under any other time constraints as required by theapplication. Enforcing appropriate coding speed is one function ofController (550). Controller controls other functional units asdescribed below and is functionally coupled to these units. The couplingis not depicted for clarity. Parameters set by controller can includerate control related parameters (picture skip, quantizer, lambda valueof rate-distortion optimization techniques, . . . ), picture size, groupof pictures (GOP) layout, maximum motion vector search range, and soforth. A person skilled in the art can readily identify other functionsof controller (550) as they may pertain to video encoder (303) optimizedfor a certain system design.

Some video encoders operate in what a person skilled in the art readilyrecognizes as a “coding loop.” As an oversimplified description, acoding loop can consist of the encoding part of an encoder (530)(“source coder” henceforth) (responsible for creating symbols based onan input picture to be coded, and a reference picture(s)), and a (local)decoder (533) embedded in the encoder (303) that reconstructs thesymbols to create the sample data that a (remote) decoder also wouldcreate (as any compression between symbols and coded video bitstream islossless in the video compression technologies considered in thedisclosed subject matter). That reconstructed sample stream is input tothe reference picture memory (534). As the decoding of a symbol streamleads to bit-exact results independent of decoder location (local orremote), the reference picture buffer content is also bit exact betweenlocal encoder and remote encoder. In other words, the prediction part ofan encoder “sees” as reference picture samples exactly the same samplevalues as a decoder would “see” when using prediction during decoding.This fundamental principle of reference picture synchronicity (andresulting drift, if synchronicity cannot be maintained, for examplebecause of channel errors) is well known to a person skilled in the art.

The operation of the “local” decoder (533) can be the same as of a“remote” decoder (310), which has already been described in detail abovein conjunction with FIG. 4 . Briefly referring also to FIG. 4 , however,as symbols are available and en/decoding of symbols to a coded videosequence by entropy coder (545) and parser (420) can be lossless, theentropy decoding parts of decoder (310), including channel (412),receiver (410), buffer (415), and parser (420) may not be fullyimplemented in local decoder (533).

An observation that can be made at this point is that any decodertechnology except the parsing/entropy decoding that is present in adecoder also necessarily needs to be present, in substantially identicalfunctional form, in a corresponding encoder. The description of encodertechnologies can be abbreviated as they are the inverse of thecomprehensively described decoder technologies. Only in certain areas amore detail description is required and provided below.

As part of its operation, the source coder (530) may perform motioncompensated predictive coding, which codes an input frame predictivelywith reference to one or more previously-coded frames from the videosequence that were designated as “reference frames.” In this manner, thecoding engine (532) codes differences between pixel blocks of an inputframe and pixel blocks of reference frame(s) that may be selected asprediction reference(s) to the input frame.

The local video decoder (533) may decode coded video data of frames thatmay be designated as reference frames, based on symbols created by thesource coder (530). Operations of the coding engine (532) mayadvantageously be lossy processes. When the coded video data may bedecoded at a video decoder (not shown in FIG. 4 ), the reconstructedvideo sequence typically may be a replica of the source video sequencewith some errors. The local video decoder (533) replicates decodingprocesses that may be performed by the video decoder on reference framesand may cause reconstructed reference frames to be stored in thereference picture cache (534). In this manner, the encoder (303) maystore copies of reconstructed reference frames locally that have commoncontent as the reconstructed reference frames that will be obtained by afar-end video decoder (absent transmission errors).

The predictor (535) may perform prediction searches for the codingengine (532). That is, for a new frame to be coded, the predictor (535)may search the reference picture memory (534) for sample data (ascandidate reference pixel blocks) or certain metadata such as referencepicture motion vectors, block shapes, and so on, that may serve as anappropriate prediction reference for the new pictures. The predictor(535) may operate on a sample block-by-pixel block basis to findappropriate prediction references. In some cases, as determined bysearch results obtained by the predictor (535), an input picture mayhave prediction references drawn from multiple reference pictures storedin the reference picture memory (534).

The controller (550) may manage coding operations of the video coder(530), including, for example, setting of parameters and subgroupparameters used for encoding the video data.

Output of all aforementioned functional units may be subjected toentropy coding in the entropy coder (545). The entropy coder translatesthe symbols as generated by the various functional units into a codedvideo sequence, by loss-less compressing the symbols according totechnologies known to a person skilled in the art as, for exampleHuffman coding, variable length coding, arithmetic coding, and so forth.

The transmitter (540) may buffer the coded video sequence(s) as createdby the entropy coder (545) to prepare it for transmission via acommunication channel (560), which may be a hardware/software link to astorage device that may store the encoded video data. The transmitter(540) may merge coded video data from the video coder (530) with otherdata to be transmitted, for example, coded audio data and/or ancillarydata streams (sources not shown).

The controller (550) may manage operation of the encoder (303). Duringcoding, the controller (550) may assign to each coded picture a certaincoded picture type, which may affect the coding techniques that may beapplied to the respective picture. For example, pictures often may beassigned as one of the following frame types:

An Intra Picture (I picture) may be one that may be coded and decodedwithout using any other frame in the sequence as a source of prediction.Some video codecs allow for different types of Intra pictures,including, for example Independent Decoder Refresh Pictures. A personskilled in the art is aware of those variants of I pictures and theirrespective applications and features.

A Predictive picture (P picture) may be one that may be coded anddecoded using intra prediction or inter prediction using at most onemotion vector and reference index to predict the sample values of eachblock.

A Bi-directionally Predictive Picture (B Picture) may be one that may becoded and decoded using intra prediction or inter prediction using atmost two motion vectors and reference indices to predict the samplevalues of each block. Similarly, multiple-predictive pictures can usemore than two reference pictures and associated metadata for thereconstruction of a single block.

Source pictures commonly may be subdivided spatially into a plurality ofsample blocks (for example, blocks of 4×4, 8×8, 4×8, or 16×16 sampleseach) and coded on a block-by-block basis. Blocks may be codedpredictively with reference to other (already coded) blocks asdetermined by the coding assignment applied to the blocks' respectivepictures. For example, blocks of I pictures may be codednon-predictively or they may be coded predictively with reference toalready coded blocks of the same picture (spatial prediction or intraprediction). Pixel blocks of P pictures may be coded non-predictively,via spatial prediction or via temporal prediction with reference to onepreviously coded reference pictures. Blocks of B pictures may be codednon-predictively, via spatial prediction or via temporal prediction withreference to one or two previously coded reference pictures.

The video coder (303) may perform coding operations according to apredetermined video coding technology or standard, such as ITU-T Rec.H.265. In its operation, the video coder (303) may perform variouscompression operations, including predictive coding operations thatexploit temporal and spatial redundancies in the input video sequence.The coded video data, therefore, may conform to a syntax specified bythe video coding technology or standard being used.

In embodiments, the transmitter (540) may transmit additional data withthe encoded video. The video coder (530) may include such data as partof the coded video sequence. Additional data may includetemporal/spatial/SNR enhancement layers, other forms of redundant datasuch as redundant pictures and slices, Supplementary EnhancementInformation (SEI) messages, Visual Usability Information (VUI) parameterset fragments, and so on.

For bit-efficient signaling and pre-notification of picture size andpartitioning information, embodiments described herein include ahierarchical signaling mechanism of the picture size and partitioninginformation. In a video parameter set (VPS), all candidates of thepicture size and partitioning information pic_size_partitioning_info( )are listed, which may be present in any layer of coded video sequences(CVS) referring to the VPS. In a sequence parameter set (SPS), indexesare listed and refer to the candidates in the VPS and additionalcandidates of the picture size and partitioning informationpic_size_partitioning_info( ), which may be referred to by an index in apicture parameter set (PPS) referring to the SPS. In the PPS, an indexis signaled and indicates the picture size and partitioning informationpic_size_partitioning_info( ) listed in the SPS, which the PPS refersto. If necessary, some parts of the picture size and partitioninginformation pic_size_partitioning_info( ) may be updated in the PPS.Specification text follows below.

The VPS is specified in Table 1 below:

TABLE 1 Descriptor video_parameter_set_rbsp( ) {  ... vps_num_pic_size_partitioning_info_minus1 ue(v)  for(i = 0; i <= vps_num_pic_size_partitioning_info_minus1; i++)  pic_size_partitioning_info( ) ... }

vps_num_pic_size_partitioning_info_minus1 plus 1 specifies a number ofthe picture size and partitioning informationpic_size_partitioning_info( ) listed in the VPS.

The SPS is specified in Table 2 below:

TABLE 2 Descriptor seq_parameter_set_rbsp( ) {  ... sps_num_pic_size_partitioning_info_minus1 ue(v)  for(i = 0; i <= sps_num_pic_size_partitioning_info_minus1; i++)  sps_additional_pic_size_partitioning_info_flag[i] u(1)   if(sps_additional_pic_size_partitioning_info_flag[i])   pic_size_partitioning_info( )   else   sps_vps_pic_size_partitioning_info_idx[i] u(1) ... }

sps_num_pic_size_partitioning_info_minus1 plus 1 specifies a number ofpicture size and the partitioning informationpic_size_partitioning_info( ) listed in the SPS.

sps_additional_pic_size_partitioning_info_flag[i] equal to 0 specifiesthat an index sps_vps_pic_size_partitioning_info_idx[i] is present.sps_additional_pic_size_partitioning_info_flag[i] equal to 1 specifiesthat an i-th picture size and partitioning informationpic_size_partitioning_info( ) listed in this SPS is present, withoutreferring to the picture size and partitioning informationpic_size_partitioning_info( ) listed in the VPS.

sps_vps_pic_size_partitioning_info_idx[i] specifies that an i-th picturesize and partitioning information pic_size_partitioning_info( ) listedin this SPS is equal to the ansps_vps_pic_size_partitioning_info_idx[i]-th picture size andpartitioning information pic_size_partitioning_info( ) listed in the VPSthat this SPS refers to.

The PPS is specified in Table 3 below:

TABLE 3 Descriptor pic_parameter_set_rbsp( ) {  ... pps_sps_pic_size_partitioning_info_idx u(1) pps_pic_size_partitioning_info_update_flag u(1) if(pps_pic_size_partitioning_info_update_flag)  pic_size_partitioning_update_info( ) ... }

pps_sps_pic_size_partitioning_info_idx specifies that picture size andpartitioning information pic_size_partitioning_info( ) of each codedpicture referring to this PPS is equal to apps_sps_pic_size_partitioning_info_idx-th picture size and partitioninginformation pic_size_partitioning_info( ) listed in the SPS that thisPPS refers to.

pps_pic_size_partitioning_info_update_flag equal to 1 specifies that anupdate of the picture size and partitioning informationpic_size_partitioning_update_info( ) is present in the PPS.

The picture size and partitioning informationpic_size_partitioning_info( ) is specified in Table 4 below:

TABLE 4 Descriptor pic_size_partitioning_info( ) { pic_width_in_luma_samples u(16)  pic_height_in_luma_samples u(16) conf_win_present_flag u(1)  if(conf_win_present_flag)   conf_win_info()  tile_brick_partitioning_present_flag u(1) if(tile_brick_partitioning_present_flag) {  tile_brick_partitioning_info( )   rect_slice_partitioning_present_flagu(1)   if(rect_slice_partitioning_present_flag)   rect_slice_partitioning_info( )   subpic_partitioning_present_flagu(1)   if(subpic_partitioning_present_flag) {   subpic_partitioning_info( )    subpic_conf_win_present_flag u(1)   if(subpic_conf_win_present_flag)    subpic_conf_win_partitioning_info( )   }  } }

conf_win_present_flag equal to 1 specifies that conf_win_info( ) ispresent in this picture size and partitioning informationpie_size_partitioning_info( ). conf_win_present_flag equal to 0specifies that conf_win_info( ) is not present in this picture size andpartitioning information pic_size_partitioning_info( ). conf_win_info( )indicates conformance window offsets.

tile_brick_partitioning_present_flag equal to 1 specifies that

tile_brick_paritioning_info( ) is present in this picture size andpartitioning information pic_size_partitioning_info( ).tile_brick_partitioning_present_flag equal to 0 specifies thattile_brick_partitioning_info( ) is not present in this picture size andpartitioning information pic_size_partitioning_info( ).tile_brick_partitioning_info( ) indicates tile brick partitioninginformation.

rect_slice_partitioning_present_flag equal to 1 specifies thatrect_slice_partitioning_info( ) is present in this picture size andpartitioning information pic_size_partitioning_info( ).rect_slice_partitioning_present_flag equal to 0 specifies thatrect_slice_partitioning_info( ) is not present in this picture size andpartitioning information pic_size_partitioning_info( ).rect_slice_partitioning_info( ) indicates rectangular slice partitioninginformation.

subpic_partitioning_present_flag equal to 1 specifies thatsubpic_partitioning_info( ) is present in this picture size andpartitioning information pic_size_partitioning_info( ).subpic_partitioning_present_flag equal to 0 specifies thatsubpic_partitioning_info( ) is not present in this picture size andpartitioning information pic_size_partitioning_info( ).subpic_partitioning_info( ) indicates sub-picture partitioninginformation.

subpic_conf_win_present_flag equal to 1 specifies thatsubpic_conf_win_info( ) is present in this picture size and partitioninginformation pic_size_partitioning_info( ). subpic_conf_win_present_flagequal to 0 specifies that subpic_conf_win_info( ) is not present in thispicture size and partitioning information pic_size_partitioning_info( ).subpic_conf_win_info( ) indicates sub-picture conformance windowoffsets.

pic_size_partitioning_update_info( ) specifies the update of the picturesize and partitioning information pic_size_partitioning_info( ), and isspecified in Table 5 below:

TABLE 5 Descriptor pic_size_partitioning_update_info( ) { pic_size_update_flag u(1)  if(pic_size_update_flag) {  updated_pic_width_in_luma_samples u(16)  updated_pic_height_in_luma_samples u(16)  }  conf_win_update_flag u(1) if(conf_win_update_flag)   conf_win_info( ) tile_brick_partitioning_update_flag u(1) if(tile_brick_partitioning_update_flag)   tile_brick_partitioning_info()  rect_slice_partitioning_update_flag u(1) if(rect_slice_partitioning_update_flag)   rect_slice_partitioning_info()  subpic_partitioning_update_flag u(1) if(subpic_partitioning_update_flag)   subpic_partitioning_info( ) subpic_conf_win_update_flag u(1)  if(subpic_conf_win_update_flag)  subpic_conf_win_partitioning_info( ) }

conf_win_update_flag equal to 1 specifies that the currentconf_win_info( ) is updated with the conf_win_info( ) in thispic_size_partitioning_update_info( ). conf_win_update_flag equal to 0specifies that the current conf_win_info( ) is not updated.

tile_brick_partitioning_update_flag equal to 1 specifies that thecurrent tile_brick_partitioning_info( ) is updated with thetile_brick_partitioning_info( ) in thispic_size_partitioning_update_info( ). conf_win_update_flag equal to 0specifies that the current tile_brick_partitioning_info( ) is notupdated.

rect_slice_partitioning_update_flag equal to 1 specifies that thecurrent rect_slice_partitioning_info( ) is updated with therect_slice_partitioning_info( ) in thispic_size_partitioning_update_info( ).rect_slice_partitioning_update_flag equal to 0 specifies that thecurrent rect_slice_partitioning_info( ) is not updated.

subpic_partitioning_update_flag equal to 1 specifies that the currentsubpic_partitioning_info( ) is updated with thesubpic_partitioning_info( ) in this pic_size_partitioning_update_info(). subpic_partitioning_update_flag equal to 0 specifies that the currentsubpic_partitioning_info( ) is not updated.

subpic_conf_win_update_flag equal to 1 specifies that the currentsubpic_conf_win_info( ) is updated with the subpic_conf_win_info( ) inthis pic_size_partitioning_update_info( ). subpic_conf_win_update_flagequal to 0 specifies that the current subpic_conf_win_info( ) is notupdated.

The obtained picture size and partitioning informationpic_size_partitioning_info( ) is used to decode the coded picture, e.g.,by the decoder (310). The picture size and partitioning information ofthe coded picture is signaled in the VPS, SPS and PPS as describedabove, e.g., by the encoder (303).

FIG. 6 is a flowchart illustrating a method (600) of efficientsignalizing of picture size and partitioning information in a videobitstream, according to embodiments. In some implementations, one ormore process blocks of FIG. 6 may be performed by the decoder (310). Insome implementations, one or more process blocks of FIG. 6 may beperformed by another device or a group of devices separate from orincluding the decoder (310), such as the encoder (303).

Referring to FIG. 6 , in a first block (610), the method (600) includesobtaining, from an SPS to which a coded picture refers, a flagindicating whether the picture size and partitioning information of thecoded picture is included in the SPS.

In a second block (620), the method (600) includes determining whetherthe obtained flag indicates that the picture size and partitioninginformation is included in the SPS.

In a third block (630), the method (600) includes, based on the flagbeing determined to indicate that the picture size and partitioninginformation is included in the SPS, obtaining, from the SPS, the picturesize and partitioning information.

In a fourth block (640), the method (600) includes, based on the flagbeing determined to indicate that the picture size and partitioninginformation is not included in the SPS, obtaining, from a VPS, thepicture size and partitioning information that is included in the VPS.

The method (600) may further include obtaining, from the SPS, a numberof picture size and partitioning information included in the SPS, anddetermining whether an index is less than or equal to the obtainednumber of picture size and partitioning information included in the SPS.

The method (600) may further include, based on the index beingdetermined to be less than or equal to the number of picture size andpartitioning information included in the SPS, incrementing the index,and obtaining, from the SPS, another flag indicating whether additionalpicture size and partitioning information is included in the SPS, theother flag corresponding to the incremented index. The method (600) mayfurther include determining whether the obtained other flag indicatesthat the additional picture size and partitioning information isincluded in the SPS, based on the other flag being determined toindicate that the additional picture size and partitioning informationis included in the SPS, obtaining, from the SPS, the additional picturesize and partitioning information, and based on the other flag beingdetermined to indicate that the additional picture size and partitioninginformation is not included in the SPS, obtaining, from the VPS, theadditional picture size and partitioning information that is included inthe VPS.

The picture size and partitioning information may include any one or anycombination of conformance window offsets of the coded picture, tilebrick partitioning information of the coded picture, rectangular slicepartitioning information of the coded picture, sub-picture partitioninginformation of the coded picture and sub-picture conformance windowoffsets of the coded picture.

Although FIG. 6 shows example blocks of the method (600), in someimplementations, the method (600) may include additional blocks, fewerblocks, different blocks, or differently arranged blocks than thosedepicted in FIG. 6 . Additionally, or alternatively, two or more of theblocks of the method (600) may be performed in parallel.

FIG. 7 is a flowchart illustrating a method (700) of efficientsignalizing of picture size and partitioning information in a videobitstream, according to embodiments. In some implementations, one ormore process blocks of FIG. 7 may be performed by the decoder (310). Insome implementations, one or more process blocks of FIG. 7 may beperformed by another device or a group of devices separate from orincluding the decoder (310), such as the encoder (303).

Referring to FIG. 7 , in a first block (710), the method (700) includesobtaining, from a PPS to which the coded picture refers, an indexindicating that the picture size and partitioning information isincluded in the SPS.

In a second block (720), the method (700) includes, based on the indexbeing obtained, obtaining, from the SPS, the picture size andpartitioning information.

The method (700) may further include obtaining, from a picture parameterset (PPS) to which the coded picture refers, another flag indicatingwhether the picture size and partitioning information is updated in thePPS, and determining whether the obtained other flag indicates that thepicture size and partitioning information is updated in the PPS. Themethod (700) may further include, based on the obtained other flag beingdetermined to indicate that the picture size and partitioninginformation is updated in the PPS, obtaining, from the PPS, the updatedpicture size and partitioning information.

The updated picture size and partitioning information may include anyone or any combination of conformance window offsets of the codedpicture, tile brick partitioning information of the coded picture,rectangular slice partitioning information of the coded picture,sub-picture partitioning information of the coded picture andsub-picture conformance window offsets of the coded picture that areupdated.

Although FIG. 7 shows example blocks of the method (700), in someimplementations, the method (700) may include additional blocks, fewerblocks, different blocks, or differently arranged blocks than thosedepicted in FIG. 7 . Additionally, or alternatively, two or more of theblocks of the method (700) may be performed in parallel.

Further, the proposed methods may be implemented by processing circuitry(e.g., one or more processors or one or more integrated circuits). In anexample, the one or more processors execute a program that is stored ina non-transitory computer-readable medium to perform one or more of theproposed methods.

FIG. 8 is a simplified block diagram of an apparatus (800) for efficientsignalizing of picture size and partitioning information in a videobitstream, according to embodiments.

Referring to FIG. 8 , the apparatus (800) includes first obtaining code(810), first determining code (820), second obtaining code (830) andthird obtaining code (840).

The first obtaining code (810) is configured to cause at least oneprocessor to obtain, from a SPS to which a coded picture refers, a flagindicating whether the picture size and partitioning information of thecoded picture is included in the SPS.

The first determining code (820) is configured to cause the at least oneprocessor to determine whether the obtained flag indicates that thepicture size and partitioning information is included in the SPS.

The second obtaining code (830) is configured to cause the at least oneprocessor to, based on the flag being determined to indicate that thepicture size and partitioning information is included in the SPS,obtain, from the SPS, the picture size and partitioning information.

The third obtaining code (840) is configured to cause the at least oneprocessor to, based on the flag being determined to indicate that thepicture size and partitioning information is not included in the SPS,obtain, from a video parameter set (VPS), the picture size andpartitioning information that is included in the VPS.

The apparatus (800) may further include fourth obtaining code (850)configured to cause the at least one processor to obtain, from the SPS,a number of picture size and partitioning information included in theSPS, and second determining code (860) configured to cause the at leastone processor to determine whether an index is less than or equal to theobtained number of picture size and partitioning information included inthe SPS.

The apparatus (800) may further include incrementing code (870)configured to cause the at least one processor to, based on the indexbeing determined to be less than or equal to the number of picture sizeand partitioning information included in the SPS, increment the index.

The first obtaining code (810) may be further configured to cause the atleast one processor to obtain, from the SPS, another flag indicatingwhether additional picture size and partitioning information is includedin the SPS, the other flag corresponding to the incremented index.

The first determining code (820) may be further configured to cause theat least one processor to determine whether the obtained other flagindicates that the additional picture size and partitioning informationis included in the SPS.

The second obtaining code (830) may be further configured to cause theat least one processor to, based on the other flag being determined toindicate that the additional picture size and partitioning informationis included in the SPS, obtain, from the SPS, the additional picturesize and partitioning information.

The third obtaining code (840) may be further configured to cause the atleast one processor to, based on the other flag being determined toindicate that the additional picture size and partitioning informationis not included in the SPS, obtain, from the VPS, the additional picturesize and partitioning information that is included in the VPS.

The apparatus (800) may further include fourth obtaining code (850)configured to cause the at least one processor to obtain, from a pictureparameter set (PPS) to which the coded picture refers, an indexindicating that the picture size and partitioning information isincluded in the SPS, and fifth obtaining code (880) configured to causethe at least one processor to, based on the index being obtained,obtain, from the SPS, the picture size and partitioning information.

The apparatus (800) may further include fourth obtaining code (850)configured to cause the at least one processor to obtain, from a pictureparameter set (PPS) to which the coded picture refers, another flagindicating whether the picture size and partitioning information isupdated in the PPS, second determining code (860) configured to causethe at least one processor to determine whether the obtained other flagindicates that the picture size and partitioning information is updatedin the PPS, and fifth obtaining code (880) configured to cause the atleast one processor to, based on the obtained other flag beingdetermined to indicate that the picture size and partitioninginformation is updated in the PPS, obtain, from the PPS, the updatedpicture size and partitioning information.

The updated picture size and partitioning information may include anyone or any combination of conformance window offsets of the codedpicture, tile brick partitioning information of the coded picture,rectangular slice partitioning information of the coded picture,sub-picture partitioning information of the coded picture andsub-picture conformance window offsets of the coded picture that areupdated.

The picture size and partitioning information may include any one or anycombination of conformance window offsets of the coded picture, tilebrick partitioning information of the coded picture, rectangular slicepartitioning information of the coded picture, sub-picture partitioninginformation of the coded picture and sub-picture conformance windowoffsets of the coded picture.

FIG. 9 is a diagram of a computer system (900) suitable for implementingembodiments.

The computer software can be coded using any suitable machine code orcomputer language, that may be subject to assembly, compilation,linking, or like mechanisms to create code including instructions thatcan be executed directly, or through interpretation, micro-codeexecution, and the like, by computer central processing units (CPUs),Graphics Processing Units (GPUs), and the like.

The instructions can be executed on various types of computers orcomponents thereof, including, for example, personal computers, tabletcomputers, servers, smartphones, gaming devices, internet of thingsdevices, and the like.

The components shown in FIG. 9 for computer system (900) are examples innature and are not intended to suggest any limitation as to the scope ofuse or functionality of the computer software implementing embodiments.Neither should the configuration of components be interpreted as havingany dependency or requirement relating to any one or combination ofcomponents illustrated in embodiments of a computer system (900).

Computer system (900) may include certain human interface input devices.Such a human interface input device may be responsive to input by one ormore human users through, for example, tactile input (such as:keystrokes, swipes, data glove movements), audio input (such as: voice,clapping), visual input (such as: gestures), olfactory input (notdepicted). The human interface devices can also be used to capturecertain media not necessarily directly related to conscious input by ahuman, such as audio (such as: speech, music, ambient sound), images(such as: scanned images, photographic images obtain from a still imagecamera), video (such as two-dimensional video, three-dimensional videoincluding stereoscopic video).

Input human interface devices may include one or more of (only one ofeach depicted): keyboard (901), mouse (902), trackpad (903), touchscreen (910), data-glove, joystick (905), microphone (906), scanner(907), camera (908).

Computer system (900) may also include certain human interface outputdevices. Such human interface output devices may be stimulating thesenses of one or more human users through, for example, tactile output,sound, light, and smell/taste. Such human interface output devices mayinclude tactile output devices (for example tactile feedback by thetouch-screen (910), data-glove, or joystick (905), but there can also betactile feedback devices that do not serve as input devices), audiooutput devices (such as: speakers (909), headphones (not depicted)),visual output devices (such as screens (910) to include cathode ray tube(CRT) screens, liquid-crystal display (LCD) screens, plasma screens,organic light-emitting diode (OLED) screens, each with or withouttouch-screen input capability, each with or without tactile feedbackcapability-some of which may be capable to output two dimensional visualoutput or more than three dimensional output through means such asstereographic output; virtual-reality glasses (not depicted),holographic displays and smoke tanks (not depicted)), and printers (notdepicted). A graphics adapter (950) generates and outputs images to thetouch-screen (910).

Computer system (900) can also include human accessible storage devicesand their associated media such as optical media including CD/DVD ROM/RW(920) with CD/DVD or the like media (921), thumb-drive (922), removablehard drive or solid state drive (923), legacy magnetic media such astape and floppy disc (not depicted), specialized ROM/ASIC/PLD baseddevices such as security dongles (not depicted), and the like.

Those skilled in the art should also understand that term “computerreadable media” as used in connection with the presently disclosedsubject matter does not encompass transmission media, carrier waves, orother transitory signals.

Computer system (900) can also include interface(s) to one or morecommunication networks (955). Networks (955) can for example bewireless, wireline, optical. Networks (955) can further be local,wide-area, metropolitan, vehicular and industrial, real-time,delay-tolerant, and so on. Examples of networks (955) include local areanetworks such as Ethernet, wireless LANs, cellular networks to includeglobal systems for mobile communications (GSM), third generation (3G),fourth generation (4G), fifth generation (5G), Long-Term Evolution(LTE), and the like, TV wireline or wireless wide area digital networksto include cable TV, satellite TV, and terrestrial broadcast TV,vehicular and industrial to include CANBus, and so forth. Certainnetworks (955) commonly require external network interface adapters thatattached to certain general purpose data ports or peripheral buses((949)) (such as, for example universal serial bus (USB) ports of thecomputer system (900); others are commonly integrated into the core ofthe computer system (900) by attachment to a system bus as describedbelow (for example Ethernet interface into a PC computer system orcellular network interface (954) into a smartphone computer system).Using any of these networks (955), computer system (900) can communicatewith other entities. Such communication can be uni-directional, receiveonly (for example, broadcast TV), uni-directional send-only (for exampleCANbus to certain CANbus devices), or bi-directional, for example toother computer systems using local or wide area digital networks.Certain protocols and protocol stacks can be used on each of thosenetworks (955) and network interfaces (954) as described above.

Aforementioned human interface devices, human-accessible storagedevices, and network interfaces (954) can be attached to a core (940) ofthe computer system (900).

The core (940) can include one or more Central Processing Units (CPU)(941), Graphics Processing Units (GPU) (942), specialized programmableprocessing units in the form of Field Programmable Gate Areas (FPGA)(943), hardware accelerators (944) for certain tasks, and so forth.These devices, along with Read-only memory (ROM) (945), Random-accessmemory (RAM) (946), internal mass storage such as internal non-useraccessible hard drives, solid-state drives (SSDs), and the like (947),may be connected through a system bus (948). In some computer systems,the system bus (948) can be accessible in the form of one or morephysical plugs to enable extensions by additional CPUs, GPU, and thelike. The peripheral devices can be attached either directly to thecore's system bus (948), or through a peripheral bus (949).Architectures for a peripheral bus include peripheral componentinterconnect (PCI), USB, and the like.

CPUs (941), GPUs (942), FPGAs (943), and accelerators (944) can executecertain instructions that, in combination, can make up theaforementioned computer code. That computer code can be stored in ROM(945) or RAM (946). Transitional data can also be stored in RAM (946),whereas permanent data can be stored for example, in the internal massstorage (947). Fast storage and retrieve to any of the memory devicescan be enabled through the use of cache memory, that can be closelyassociated with one or more CPU (941), GPU (942), mass storage (947),ROM (945), RAM (946), and the like.

The computer readable media can have computer code thereon forperforming various computer-implemented operations. The media andcomputer code can be those specially designed and constructed for thepurposes of embodiments, or they can be of the kind well known andavailable to those having skill in the computer software arts.

As an example and not by way of limitation, the computer system havingarchitecture (900), and specifically the core (940) can providefunctionality as a result of processor(s) (including CPUs, GPUs, FPGA,accelerators, and the like) executing software embodied in one or moretangible, computer-readable media. Such computer-readable media can bemedia associated with user-accessible mass storage as introduced above,as well as certain storage of the core (940) that are of non-transitorynature, such as core-internal mass storage (947) or ROM (945). Thesoftware implementing various embodiments can be stored in such devicesand executed by core (940). A computer-readable medium can include oneor more memory devices or chips, according to particular needs. Thesoftware can cause the core (940) and specifically the processorstherein (including CPU, GPU, FPGA, and the like) to execute particularprocesses or particular parts of particular processes described herein,including defining data structures stored in RAM (946) and modifyingsuch data structures according to the processes defined by the software.In addition or as an alternative, the computer system can providefunctionality as a result of logic hardwired or otherwise embodied in acircuit (for example: accelerator (944)), which can operate in place ofor together with software to execute particular processes or particularparts of particular processes described herein. Reference to softwarecan encompass logic, and vice versa, where appropriate. Reference to acomputer-readable media can encompass a circuit (such as an integratedcircuit (IC)) storing software for execution, a circuit embodying logicfor execution, or both, where appropriate. Embodiments encompass anysuitable combination of hardware and software.

While this disclosure has described several embodiments, there arealterations, permutations, and various substitute equivalents, whichfall within the scope of the disclosure. It will thus be appreciatedthat those skilled in the art will be able to devise numerous systemsand methods that, although not explicitly shown or described herein,embody the principles of the disclosure and are thus within the spiritand scope thereof.

1. A method of efficient signalizing of picture size in a videobitstream via a hierarchical mechanism, the method being performed by atleast one processor, and the method comprising: receiving a picture;generating a picture parameter set (PPS) comprising a first syntaxelement associated with the picture, the first syntax element indicatinga picture size comprising a width and a height associated with thepicture, wherein the first syntax element refers to a second syntaxelement in a sequence parameter set (SPS); generating the SPS comprisingthe second syntax element associated with the picture, the second syntaxelement indicating the picture size comprising the width and the heightassociated with the picture, and wherein the second syntax elementrefers to a third syntax element in a video parameter set (VPS);generating the VPS comprising the third syntax element associated withthe picture, the third syntax element indicating the picture sizecomprising the width and the height associated with the picture, whereinthe third syntax element is referred to by at least a layer of a videosequence; and encoding the picture based on values of the first syntaxelement, the second syntax element, and the third syntax element.
 2. Themethod of claim 1, further comprising: determining, from the SPS, anumber of picture size information included in the SPS; determiningwhether an index is less than or equal to the number of picture sizeinformation included in the SPS; and based on the index being determinedto be less than or equal to the number of picture size informationincluded in the SPS, incrementing the index.
 3. The method of claim 2,wherein a flag is obtained based on the incremented index, wherein theflag indicates whether additional picture size information is includedin the SPS.
 4. The method of claim 1, further comprising: adding anindex into the PPS, the index indicating that picture size informationis included in the SPS; and based on the index being added, obtaining,from the SPS, the picture size information.
 5. The method of claim 1,further comprising: adding an update flag in the PPS associated with thepicture, the update flag indicating whether picture size information isupdated in the PPS; determining whether the update flag indicates thatthe picture size information is updated in the PPS; and based on theupdate flag being determined to indicate that the picture sizeinformation is updated in the PPS, updating the updated picture sizeinformation in the PPS.
 6. The method of claim 5, wherein the updatedpicture size information comprises any one or more of conformance windowoffsets of the picture, tile brick partitioning information of thepicture, rectangular slice partitioning information of the picture,sub-picture partitioning information of the picture and sub-pictureconformance window offsets of the picture that are updated.
 7. Themethod of claim 2, wherein the picture size information comprises anyone or any combination of conformance window offsets of the picture,tile brick partitioning information of the picture, rectangular slicepartitioning information of the picture, sub-picture partitioninginformation of the picture and sub-picture conformance window offsets ofthe picture.
 8. An apparatus for efficient signalizing of picture sizeand partitioning information in a video bitstream, the apparatuscomprising: at least one memory configured to store computer programcode; and at least one processor configured to access the at least onememory and operate according to the computer program code, the computerprogram code comprising: receiving code configured to cause the at leastone processor to receive a picture; first generating code configured tocause the at least one processor to generate a picture parameter set(PPS) comprising a first syntax element associated with the picture, thefirst syntax element indicating a picture size comprising a width and aheight associated with the picture, wherein the first syntax elementrefers to a second syntax element in a sequence parameter set (SPS);second generating code configured to cause the at least one processor togenerate the SPS comprising the second syntax element associated withthe picture, the second syntax element indicating the picture sizecomprising the width and the height associated with the picture, whereinthe second syntax element refers to a third syntax element in a videoparameter set (VPS); third generating code configured to cause the atleast one processor to generate the VPS comprising the third syntaxelement associated with the picture, the third syntax element indicatingthe picture size comprising the width and the height associated with thepicture, wherein the third syntax element is referred to by at least alayer of a video sequence; and decoding code configured to cause the atleast one processor to decode the picture based on values of the firstsyntax element, the second syntax element, and the third syntax element.9. The apparatus of claim 8, the program code further comprising: firstdetermining code configured to cause the at least one processor todetermine, from the SPS, a number of picture size information includedin the SPS; second determining code configured to cause the at least oneprocessor to determine whether an index is less than or equal to thenumber of picture size information included in the SPS; and incrementingcode configured to cause the at least one processor to, based on theindex being determined to be less than or equal to the number of picturesize information included in the SPS, increment the index.
 10. Theapparatus of claim 9, wherein a flag is obtained based on theincremented index, wherein the flag indicates whether additional picturesize information is included in the SPS.
 11. The apparatus of claim 8,wherein the program code further comprises: first inserting codeconfigured to cause the at least one processor to insert an index intothe PPS, the index indicating that picture size information is includedin the SPS; and first obtaining code configured to cause the at leastone processor to, based on the index being inserted, obtain, from theSPS, the picture size information.
 12. The apparatus of claim 8, whereinthe program code further comprises: first updating code configured tocause the at least one processor to insert an update flag into the PPSassociated with the picture, the update flag indicating whether picturesize information is updated in the PPS; third determining codeconfigured to cause the at least one processor to determine whether theupdate flag indicates that the picture size information is updated inthe PPS; and second updating code configured to cause the at least oneprocessor to, based on the update flag being determined to indicate thatthe picture size information is updated in the PPS, update the updatedpicture size information in the PPS.
 13. The apparatus of claim 12,wherein the updated picture size information comprises any one or moreof conformance window offsets of the picture, tile brick partitioninginformation of the picture, rectangular slice partitioning informationof the picture, sub-picture partitioning information of the picture andsub-picture conformance window offsets of the picture that are updated.14. The apparatus of claim 9, wherein the picture size informationcomprises any one or any combination of conformance window offsets ofthe picture, tile brick partitioning information of the picture,rectangular slice partitioning information of the picture, sub-picturepartitioning information of the picture and sub-picture conformancewindow offsets of the picture.
 15. A non-transitory computer-readablestorage medium storing instructions that cause at least one processorto: receive a picture; generate a picture parameter set (PPS) comprisinga first syntax element associated with the picture, the first syntaxelement indicating a picture size comprising a width and a heightassociated with the picture, wherein the first syntax element refers toa second syntax element in a sequence parameter set (SPS); generate theSPS comprising the second syntax element associated with the picture,the second syntax element indicating the picture size comprising thewidth and the height associated with the picture, wherein the secondsyntax element refers to a third syntax element in a video parameter set(VPS); generate the VPS comprising the third syntax element associatedwith the picture, the third syntax element indicating the picture sizecomprising the width and the height associated with the picture, whereinthe third syntax element is referred to by at least a layer of a videosequence; encode the picture based on values of the first syntaxelement, the second syntax element, and the third syntax element;obtain, from the SPS, a number of picture size information included inthe SPS; determine whether an index is less than or equal to theobtained number of picture size information included in the SPS; andbased on the index being determined to be less than or equal to thenumber of picture size information included in the SPS, increment theindex.
 16. The non-transitory computer-readable storage medium of claim15, further comprising: obtain, from the SPS, a number of picture sizeinformation included in the SPS; determine whether an index is less thanor equal to the number of picture size information included in the SPS;and based on the index being determined to be less than or equal to thenumber of picture size information included in the SPS, increment theindex.
 17. The non-transitory computer-readable storage medium of claim16, wherein a flag is obtained based on the incremented index, whereinthe flag indicates whether additional picture size information isincluded in the SPS.
 18. The non-transitory computer-readable storagemedium of claim 15, wherein the instructions further cause the at leastone processor to: adding an index into the PPS, the index indicatingthat picture size information is included in the SPS; and based on theindex being added, obtain, from the SPS, the picture size information.19. The non-transitory computer-readable storage medium of claim 15,wherein the instructions further cause the at least one processor to:adding an update flag associated with the picture, the update flagindicating whether picture size information is updated in the PPS;determine whether the update flag indicates that the picture sizeinformation is updated in the PPS; and based on the update flag beingdetermined to indicate that the picture size information is updated inthe PPS, updating the updated picture size information in the PPS. 20.The non-transitory computer-readable storage medium of claim 16, whereinthe picture size information comprises any one or more of conformancewindow offsets of the picture, tile brick partitioning information ofthe picture, rectangular slice partitioning information of the picture,sub-picture partitioning information of the picture and sub-pictureconformance window offsets of the picture.